If the ACC plays this correctly (along with Big and Pac sisters) the SEC could end up being regionalized and isolated. Yeah the SEC may dominate a certain type of fan in the southeast, but the ACC teams all end up part of a national conference. If they agree to limit games to themselves, minus perhaps a single rivalry game each year that doesn’t count towards rankings/standings, etc. SEC basically ends up with a handful of powerhouse teams such as Bammer, Awbarn, Tex, OU, UF, A&M with the rest a bunch of wannbee perennial runners ups like the dwags, UT, SCe beating the bottom feeders like Mizzou, Vandy and those Miss schools.
Then you got the coast to coast alliance the ACC is part of, where you section it off and have 4, 16 team regions playing for a national championship each year. You divide each 16 team region into divisions of 8, have #1 play #2 in other half with winners moving to regional championship. Then regional winners playoffs, with those winners squaring off for championship. That’s 4 games max for the 2 in the championship game, it takes a month and lets the losers fill bowl games. They could basically lock the SEC out of anything meaningful except bragging about their own conference.
If the new alliance picks up the 8 remaining members of the Big 12, you have to line up another 16 from the likes of UCF, USF, BYU, Cincy, Boise, the 3 academies, Uconn, Houston, Memphis, etc take your pick from whatever gives a national major market balance where possible.